Flavor symmetry and symmetry breaking, K^0-\bar{ K}^0 mixing and possible effects of new physics on CP violation in weak decay modes D^{ \pm} \to K_{ S,L} + X^{ \pm}, (K_{ S,L} + \pi^0)_{ K^*} + X^{ \pm} (for X =\pi, \rho, a_1) and D^{ \pm}_s \to K_{ S,L} + X^{ \pm}_s, (K_{ S,L} +\pi^0)_{ K^*} + X^{ \pm}_s (for X_s = K, K^*) are analyzed. Relations between D^{ \pm} and D^{ \pm}_s decay branching ratios are obtained from the d \Leftrightarrow s subgroup of SU(3) and dominant symmetry-breaking mechanisms are investigated. A CP asymmetry of magnitude 3.3\times 10^{ -3} is shown to result in the standard model from K^0-\bar{ K}^0 mixing in the final-state. New physics affecting the doubly Cabibbo-suppressed channels might either cancel this asymmetry or enhance it up to the percent level. A comparison between the CP asymmetries in D^{ \pm}_{ (s)} \to K_{ S} X^{ \pm}_{ (s)} and D^{ \pm}_{ (s)} \to K_L X^{ \pm}_{ (s)} can pin down effects of new physics.
Categories: hep-ph hep-ex